METHOD AND DEVICE FOR SORTING PRODUCTS

Description

[0001] The present invention concerns a method and a device for sorting products.

[0002] It is meant in particular for removing certain products from a product stream.

[0003] In particular, it aims a method and a device which is very suitable to be applied in the food industry, for example for sorting out non-food products from certain foods, in particular leaves, branches and pieces of waste such as wood, plastic, stones, etc.

[0004] However, the products to be sorted can also be foods of different quality, whereby a quality selection is made by means of the sorting. The method can also be used to separate good and bad products.

[0005] It is known from the international patent application WO 96/00621 to illuminate the products to be sorted with a light beam and to subsequently carry out a selection on the basis of the light which is collected by means of reflection, fluorescence or such. The collected light is treated in a spectroscopic analysis device which delivers an output signal for the selection as a function of the analysis. As use is made of a spectral analysis, whereby the entire spectrum has to be analysed every time, this system is very expensive since it requires a spectroscopic analysis device.

[0006] A method is known from the international patent application WO 97/42489 to determine the ripeness of seeds by means of the fluorescence of the chlorophyll in the seeds, after they have been illuminated. The described method makes it possible to shine light through the seeds one after the other, but it does not offer a practical embodiment for the treatment of large amounts at once. Moreover, the described method only leads to a selection among seeds, but it does not go in the direction of selecting strange products from foodstuff or such.

[0007] A method for sorting particles is known from the patent application GB 2.292.455, whereby the particles to be sorted are irradiated with a laser and the obtained 'Raman scattering' is used as a sorting criterion. As exposed in GB 2.292.455, normal Raman scattering is disadvantageous in that the signal obtained by means of scattering, is disturbed too much by the emission'obtained by means of fluorescence, and thus becomes difficult to detect. That is why it is suggested in GB 2.292.455 to make use of a stimulated Raman signal. However, this technique is in turn disadvantageous in that a high energy supply is necessary, requiring expensive equipment.

[0008] Document US 5,848,706 is disclosing a sorting apparatus provided with a background that presents the same degree of reflectivity, color, luminance as the desired products. However, such a background is not suitable to sort waste from products containing chlorophyll, when this waste presents the same reflectivity, color or luminance as the desired products.

[0009] In general, the invention aims a method and a device which make it possible to carry out a very efficient and reliable selection in a large product stream, such that the sorting can be applied at an industrial level for the treatment of large quantities of products.

[0010] In particular, according to a number of preferred embodiments, it aims a method and a device whereby the use of expensive spectrographical analysis equipment is excluded, and whereby large quantities can be treated.

[0011] To this aim, the invention in the first place concerns a method for sorting products whereby waste is separated from products containing chlorophyll according to claim 1

[0012] By making use of a wide product stream which is scanned over the width on the one hand, and by making use of emitted light on the other hand, it is possible to make a particularly fast and efficient selection with great certainty and with a minimum of faults, such as opposed to for example the above-mentioned known systems, as well as the systems which are available on the market, whereby the selection is exclusively made on the basis of reflected light, in particular by means of colour recognition. By making use of 'fluorescence', which is a spontaneous 'emission' as will be further explained, the effect which is felt as being disadvantageous according to GB 2.292.455, will be used as an essential characteristic according to the invention to carry out the selection. This effect is particularly useful when sorting specific foods, whereby Raman scattering does not offer an efficient solution.

[0013] In order to observe the light which is emitted by the products concerned, use is made of an optical filtering, by means of a band-pass filter. This allows for an almost instant evaluation and selection of the scanned products, as opposed to the relatively complicated and expensive spectral analysis which is applied in the method described in WO 96/00621.

[0014] The selection is made on the basis of a certain intensity value of the emitted light or of a signal corresponding to it being either exceeded or just not exceeded. As use is made of the emission in a specific spectrum, there is a very clear distinction between signals which are related to a light-emitting product and signal which are related to a non-light-emitting product, which makes it possible to make a very efficient distinction by simply verifying whether the signals either or not exceed a certain value.

[0015] The light is cast from such a part of the spectrum that light is emitted by the products concerned in another part of the spectrum. This makes it easy to make a distinction between the emitted light and possibly directly reflected light by means of an optical band-pass filter or such.

[0016] According to the invention, use is made of the fluorescence qualities for the emission, in particular the fact that the scanned products either or not fluoresce.

[0017] More in particular, the method will be used for sorting chlorophyll-containing foods, in particular for the selection of strange products from foods.

[0018] The invention is particularly useful for separating waste from for example peas, especially for separating strange products therefrom such as stones, pieces of wood, plastic and such.

[0019] The method is applied for separating waste from products containing chlorophyll, such as for example peas, and light is emitted during the scanning having a wavelength of 640 to 680 nanometer, whereas other light is preferably excluded. Thus is obtained that only the foods containing chlorophyll, in this case the peas, start to emit light in the spectrum to be observed as a result of fluorescence. This wavelength selection can also be used for other foods containing chlorophyll, such as beans, lettuce, sprouts, etc.

[0020] In order to observe the emitted light, observations are preferably exclusively made in the wavelength range of 690 to 740 nanometer, by means of optical filtering, and in particular in a range which has a value in the order of magnitude of some 715 nanometer. In this range, the emission can be optimally observed.

[0021] According to another possibility, use is made for the emission of the light-emitting quality of certain organisms such as bacteria, fungi and such, which can be found on certain products, whereby a selection is made between the products on the basis of said emission.

[0022] A practical application thereof, not according to the invention consists in sorting foods which are affected by fungi from non-affected foods, in particular in sorting nuts or figs which are affected by aflatoxins. Preferably, there will be an excitation with deep blue UV light (340 to 400 nm). The observed emitted light will then be green. Preferably, measurements will only be carried out in the wavelength range of 440 to 550 nm in this case.

[0023] According to the invention, use is made of a background which will emit light when it is being illuminated, that is which will fluoresce, such that the light being cast will also produce an emission effect in those places where it is not cast on a product. This offers the advantage that it becomes possible to make a simple selection between light-emitting and non-light-emitting products without any special measures being required to prevent that those places where there is no product and which are observed during the scanning are regarded as places where strange products to be removed are found.

[0024] Use is preferably made here of an emitting background of a surface extending in the width of the product stream which is spherical on the side where the light is cast upon. The spherical shape promotes a very precise emission.

[0025] Practically, the above-mentioned background will consist of a cylindrical roller.

[0026] According to a variation not according to the invention, instead of using a background which emits light after light has thus been cast upon it, use can also be made of a background which constantly emits light, preferably of a wavelength which is ideal in relation to the selection to be made.

[0027] As for the emitting background, a background is provided which emits light having practically the same wavelength as the light which is emitted by the products to be treated.

[0028] In order to be able to obtain high emission values with a minimum of energy, and consequently to be able to make observations with great certainty, the scanning according to the invention is preferably carried out by means of a laser, in particular by making a laser beam move diagonally over the product stream in a systematic manner.

[0029] According to a very advantageous embodiment, a scanning system with a moving mirror, preferably a rotating polygon mirror or another optical element is used, and the emitted light is returned via the same mirror or the same optical element.

[0030] Instead of making use of a laser, the scanning can also take place in another way, for example by means of a fixed light band or a series of light points, directed onto the products which pass by over the width of the product stream, whereby at least the emitted light is observed by means of a camera, and whereby the selection is made on the basis of the evaluation of camera images.

[0031] In order to make the products move in the shape of a product stream with a certain width along the place where they are scanned, use can be made of different techniques. A practical technique consists in bringing the products in a single plane on the place where they are to be scanned, via a table, belt or such, either or not provided with longitudinal ducts or grooves.

[0032] Further, the products preferably fall down freely and the products to be separated are moved apart by means of nozzles which are erected over the width of the product stream and which are individually activated as a function of the observations made, whereby for example the products to be removed from the global product stream are blown away and are collected in a recipient.

[0033] In order to further optimise the method, the products to be sorted can be scanned from two sides, situated opposite to the product stream. This makes it possible to make a right selection with more certainty, which is particularly important when there is a possibility that products show different qualities on the front and on the back side.

[0034] It should be noted that the method of the invention can possibly be combined with another scanning process, for example with a colour sorting by means of the reflected light. In the latter case, different laser beams can be used, namely at least one laser beam to realise the above-mentioned emission in a different spectrum, and at least one laser beam for sorting for example on the basis of the normal light reflection. Practically, the different laser beams can then be simultaneously guided along the same light path according to the invention, possibly slightly shifted in relation to one another. As a result, only one polygon mirror or another optical element will be required to move the laser beams over the product stream.

[0035] Apart from the above-mentioned method, the invention also concerns a device for sorting products according to claim 16.

[0036] In order to better explain the characteristics of the invention, the following preferred embodiments are described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:

figure 1 schematically illustrates the method according to the invention;

figure 2 represents an example of a signal which is obtained during the scanning of the products concerned;

figure 3 represents a device according to the invention in perspective;

figure 4 schematically represents the device of figure 3;

figure 5 represents a section according to line V-V in figure 4;

figure 6 schematically represents a section according to line VI-VI in figure 5;

figure 7 schematically represents a variant of a device according to the invention.

[0037] Figure 1 schematically represents how the products 1-2 to be sorted are conveyed over a certain path 3 in the shape of a product stream 4 which extends in the width, in particular a certain width B. The products 1-2 are hereby schematically represented as good products 1, for example peas or other products containing chlorophyll, and the products 2 to be removed, for example strange elements such as stones, pieces of wood and plastic.

[0038] According to the invention, the product stream 4 is scanned by casting light 6 on the products 1-2 with the help of appropriate means 5 on the one hand, at least in a specific spectrum which is selected such that specific products to be sorted, in this case the products 1, emit light 7, whereas the other products 2 don't, and by observing the light 7 with the help of appropriate means 8 in a specific range of the spectrum in which the emitted light 7 is emitted on the other hand.

[0039] The means 5 hereby consist of a light source 9, preferably a laser which emits the light 6 in the shape of a ray of light, namely a laser beam 10, as well as means to systematically turn the laser beam 10 over an angle A which are not represented here, such that the product stream is scanned over the width B, in particular on the place of the line part L.

[0040] The means 8 consist of an optical filter 11 on the one hand which mainly exclusively lets the light 7 through from the spectrum range in which the emission takes place, and of a detection device 12 to observe said light 7 on the other hand.

[0041] Further, figure 1 schematically represents means 13, such as an electronic processing unit, to make a selection between the scanned products 1-2 as a function of the observed light 7, also as a function of the place on the line part L where said light 7 came from.

[0042] In order to automatically separate the products 1 and 2, means 14 are provided which in this case consist of nozzles 15 which can be individually activated and which are controlled by means of a valve unit 16 which is not further described here, as a function of the signals 17 coming from the above-mentioned processing unit. The means 14 also comprise a partition 18.

[0043] It is clear that the necessary means are further provided to separate the cast light 6 and the emitted light 7 in an appropriate manner, for example by means of a semitransparent mirror 19, as is schematically represented. Finally, another element 20 is represented in figure 1 having a surface 21 which forms an emitting background. As explained in the introduction, it preferably consists of a cylindrical roller.

[0044] The method according to the invention consists in that light 6 is cast having at least such a wavelength that one of either products 1-2, when it is irradiated by the light 6, spontaneously starts to cast or emit light at another wavelength than that of the light 6 with which it is irradiated.

[0045] Since the products 1 consist of peas or other products containing chlorophyll, in particular foods, light 7 from the spectrum of 690 to 740 nanometer will be emitted. As a result thereof is obtained that when the laser beam 10 hits a product 1, in particular a pea, light 7 is emitted. The same occurs when the laser beam 10 hits no product 1 or 2 whatsoever, whereby in this case light having practically the same wavelength is emitted due to the fluorescence of the surface 21.

[0046] If, however, the laser beam 10 hits a product 2, such as a stone or such, there will be no fluorescence, and hence no light 7 will be emitted.

[0047] By moving the laser beam 10 at a sufficiently high speed over the width B, for example at 12,000 cycles per minute, all products 1-2, which fall down freely in the given example, can be scanned without any problems.

[0048] As a result, light 7 is observed which, after being transformed, results in an electric signal E, such as represented for example in the diagram of figure 2, whereby this signal is measured out as a function of the above-mentioned width B. The parts 22 of the signal progress are hereby the result of the emission occurring with a product 1, in particular a pea, whereas the parts 23 are the result of the emission at the surface 21. The parts 24 indicate that products 2 are present which cause no emission.

[0049] Subsequently, in the means 13 forming the processing unit, an automatic selection is carried out to detect the places where the products 2 pass, on the basis of the above-mentioned signal progress. As explained in the introduction, this is preferably done on the basis of a certain value of the above-mentioned signal being either or not exceeded, in particular by checking when the signal goes beneath a certain limit value W in the case of figure 2. It is clear that, each time the signal goes beneath said value W, this means that a product 2 is being observed.

[0050] In order to efficiently remove the products 2, one or several nozzles 15 are activated, on the place where the product 2 is found, so that each such product 2 is blown out of the product stream 4, in particular behind the partition 18. As they are blown away, it may happen that a number of products 1 are also removed from the product stream 4, but since the quantity of products 2 usually is very small in relation to the quantity of products 1, also the good products 1 which are blown out of the product stream 4 will be limited in number.

[0051] Figures 3 to 6 hereafter represent a possible practical construction of a device 25 for realising the above-mentioned method in further detail.

[0052] Figure 3 shows the device 25 as a whole. This device 25 is equipped with two optical units 26 and 27 which, as is schematically represented in figures 4 and 5, make it possible for the products 1-2 to be scanned on either side. Every unit 26, 27 respectively, has a construction as is schematically represented in figure 1, as well as in figure 6 which will be described hereafter.

[0053] In order to carry the products 1-2 in the shape of a product stream 4 with a certain width but with a small thickness past the place where they are scanned, a device 25 is equipped with means 28 in the shape of a vibrating table 29, from where the products 1-2 are vibrated downward over the edge 30 of this vibrating table 29. Via a sliding surface 31 they are guided into a zone 32, where they fall down freely and where they are also scanned, as mentioned above.

[0054] The products 1 which have been let through are guided further via a discharge chute 33, whereas the removed products 2 are collected in a recipient 34 or such.

[0055] It is clear that, according to a variant, instead of a vibrating table 29, use can also be made of a conveyor belt or such. Also longitudinal ducts or grooves can be provided in the vibrating table to obtain different parallel rows of products 1-2 falling down, whereby for example each row passes exactly one nozzle 15.

[0056] Figure 6 further schematically represents how the cast light 6 and the emitted light 7 which is caught again by means of a moving mirror 35, in particular a rotating polygon mirror, can be moved over the width B of the product stream 4.

[0057] Figure 7 represents a part of a special embodiment of a device 25 according to the invention. The means for conveying the products 1-2 to be sorted in the shape of a product stream 4 over a certain path hereby mainly consist of a drum 36 which is provided with inlets 37 on its surface against which the products 1-2 are sucked, by creating a vacuum in an appropriate manner. The means for automatically making a separation as a function of the selection in this case consist of means which are not represented, in particular valves or such, which make it possible to selectively control the inlets 37 concerned, in particular to close or to open them.

[0058] The working is then mainly as follows: the product stream 4 is for example brought into contact with the surface of the drum 36 via a feed chute 38. Thanks to the suction force on the inlets 37, products 1-2 are sucked onto the surface of the drum 36, as a result of which the product stream 4 so to say continues on the surface of this drum 36.

[0059] Then, the products 1-2 are scanned by means of an optical unit 39, analogous to that of the preceding embodiment.

[0060] The surface of the drum 36 consists of a light-emitting material, like the surface 21 of the above-mentioned element 20.

[0061] By providing two ducts 40 and 41 for the separate discharge of the products 1-2 and by interrupting the sucking action on the respective inlets 37 as a function of the data obtained by means of the scanning, it is possible to carry out a separation. Above the duct 41, the inlets 37 holding products 2 are closed, such that the sucking action is interrupted and that these products 2 fall in the duct 41. Above the duct 40, the suction action of all inlets 37 is interrupted, such that all the products 1 there come loose of the drum 36.

[0062] It should be noted that, as opposed to what is schematically represented in figures 1 and 4 to 7, the width B is in reality a considerable number of times the diameter of the product 1-2. In reality, this width will usually be in the order of magnitude of 0.3 to 1 meter, but of course it can also deviate therefrom. Further, the product stream 4 in reality consists of a quantity of products 1-2 spread out over almost the entire surface of the path 3.

Claims

1. Method for sorting products, whereby waste is separated from products containing chlorophyll, characterised in that it at least consists
in conveying the products (1-2) to be sorted in the shape of a product stream (4) extending in the width (B) over a specific path (3);
in scanning the products (1-2) to be sorted over the width (B) of said product stream (4) by casting light (6) onto the products (1-2) having a wavelength of 640 to 680 nanometer such that products (1) containing chlorophyll will emit light (7), and by observing this emitted light (7) in a wavelength range of 690 to 740 nanometer;
in using an optical band-pass in order to observe the light (7) which is emitted by the products (1) concerned;
in using a background which will emit light when it is being illuminated and which will fluoresce, such that the cast light (6) will also produce an emission effect in those places where it is not cast on a product (1-2), the light emitted by the background having practically the same wavelength as the light which is emitted by the products (1) containing chlorophyll;
in making a selection between the scanned products (1-2) as a function of the observed light (7), wherein the selection is made on a certain intensity value of the emitted light (7); and
in automatically separating the products (1-2) from the above-mentioned product stream (4) as a function of said selection.

2. Method according to claim 1, characterised in that use is made of the fluorescence qualities for the emission, in particular the fact that the scanned products (1-2) either or not fluoresce.

3. Method according to any of the preceding claims, characterised in that it is used for sorting chlorophyll containing foods, in particular for the selection of nonfood products (2) from the foods.

4. Method according to any of the preceding claims, characterised in that when the emitted light (7) is observed, this is done in a range which has a value in the order of magnitude of some 715 nanometer.

5. Method according to any of the preceding claims, characterised in that, for the emitting background, use is made of a surface (21) extending in the width of the product stream (4) which is spherical on the side where the light (6) is cast upon.

6. Method according to any of the preceding claims, characterised in that the background consists of an element (20) in the shape of a cylindrical roller.

7. Method according to any of the preceding claims, characterised in that the scanning takes place by means of a laser.

8. Method according to any of the preceding claims, characterised in that the scanning is carried out by making a laser beam (10) move diagonally over the product stream (4) in a systematic manner.

9. Method according to any of the preceding claims, characterised in that use is made of a scanning system with a moving mirror (35), preferably a rotating polygon mirror, and in that the emitted light (7) is returned via the same mirror (35).

10. Method according to any of the preceding claims, characterised in that the scanning takes place by means of a fixed light band or a series of light points directed onto the products (1-2) which pass by over the width of the product stream (4), whereby at least the emitted light (7) is observed by means of a camera.

11. Method according to any of the preceding claims, characterised in that the products (1-2) are brought in a single plane on the place where they are to be scanned, via a table, in particular a vibrating table (29), belt or such, either or not provided with longitudinal ducts or grooves.

12. Method according to any of the preceding claims, characterised in that the products (1-2) fall down freely and in that the products (1-2) to be separated are moved apart by means of nozzles (15) which are erected over the width (B) of the product stream and which are activated individually or in groups as a function of the observations made.

13. Method according to any of the preceding claims, characterised in that the products (1-2) to be sorted are scanned from two sides, situated opposite to the product stream (4).

14. Method according to any of the preceding claims, characterised in that it is combined with a colour sorting whereby the sorting is done on the basis of light reflection.

15. Method according to any of the preceding claims, characterised in that different laser beams are used and in that the different laser beams are simultaneously guided along the same light path, possibly slightly shifted in relation to one another.

16. Device for sorting products according to the method of any of the preceding claims, whereby waste is separated from products containing chlorophyll, characterised in that it at least consists of the combination of
means (28) for conveying the products (1-2) to be sorted in the shape of a product stream (4) extending in the width (B) over a certain path (3);
means for scanning the products (1-2) to be sorted over the width (B) of said product stream (4), consisting of means (5) to cast light (6) having a wavelength of 640 to 680 nanometer on the products (1-2) and on a background (20) which fluoresces when being illuminated with the cast light (6) such that products (1) containing chlorophyll and the background (20) will emit light (7) having practically the same wavelength, and of means (8) to observe this emitted light in a range of 690 to 740 nanometer;
an optical band-pass filter in order to observe the light (7) which is emitted by the products (1) concerned;
means (13) to make a selection between the scanned products (1-2) as a function of a certain intensity value of the emitted light (7);
and means (14) to automatically separate the products (1-2) from the above-mentioned product stream (4) as a function of said selection.

17. Device according to claim 16, characterised in that the means (5) for casting light (6) on the products (1-2) consist of a laser generating a laser beam (10), as well as optical means which make this laser beam (10) move in the width over the product stream (4).

18. Device according to claim 16 or 17, characterised in that the means (8) for observing light (7) in the spectrum in which the emitted light (7) is cast, consist of optical means which collect the emitted light (7) and guide it to the means (13) for carrying out the selection, whereby these optical means at least comprise an optically adjusted filter(11).

19. Device according to any of claims 16 to 18, characterised in that the means (28) for conveying the products (1-2) to be sorted in the shape of a product stream (4) extending in the width (B) over a certain path (3) mainly consist of a vibrating table (29) upon which the products (1-2) are placed and are subsequently vibrated away over the edge (30) thereof.

20. Device according to any of claims 16 to 19, characterised in that the means (14) for automatically separating the products (1-2) from the above-mentioned product stream (4) as a function of the selection consist of a series of nozzles (15) which are activated as a function of the selection made and the separation to be realised.

21. Device according to any of claims 16 to 20, characterised in that the means (28) for conveying the products (1-2) to be sorted in the shape of a product stream (4) extending in the width (B) over a certain path (3) mainly consist of a drum (36) which is provided with inlets (37) on its surface against which the products (1-2) are sucked, and in that the means for automatically making a separation as a function of the selection consist of means which make it possible to selectively control the inlets (37) concerned.

22. Device according to any of claims 16 to 21, characterised in that the means for scanning the products (1-2) to be sorted over the width (B) of the product stream (4) contain one or several elements (20) forming a lightemitting background.

23. Device according to claim 22, characterised in that the above-mentioned elements (20) consist of a cylindrical roller with a fluorescent surface(21).

Ansprüche

1. Verfahren zum Sortieren von Produkten, wodurch Abfall von Produkten getrennt wird, die Chlorophyll enthalten, dadurch gekennzeichnet, dass es zumindest Folgendes aufweist:

Fördern der zu sortierenden Produkte (1-2) in Form eines Produktstroms (4), der sich über die Breite (B) eines bestimmten Pfades (3) erstreckt;

Abtasten der zu sortierenden Produkte (1-2) über die Breite des Produktstroms (4) durch Werfen von Licht (6) auf die Produkte (1-2) mit einer Wellenlänge von 640 bis 680 Nanometern, so dass Produkte (1), die Chlorophyll enthalten, Licht (7) emittieren werden, und beobachten dieses emittierten Lichtes (7) in einem Wellenbereich von 690 bis 740 Nanometer; Verwenden eines optischen Bandpasses, um das Licht (7) zu beobachten, welches von den betreffenden Produkten emittiert wird;

Verwenden eines Hintergrundes, der Licht emittieren wird, wenn er beleuchtet wird, und der Fluoreszenz zeigen wird, so dass das darauf gestrahlte Licht (6) auch einen Emissionseffekt an jenen Stellen erzeugen wird, wo es nicht auf das Produkt (1-2) geworfen wird, wobei das vom Hintergrund emittierte Licht praktisch die gleiche Wellenlänge hat, wie das Licht, welches von den Produkten (1) emittiert wird, welche Chlorophyll enthalten;

Vornehmen einer Auswahl unter den abgetasteten Produkten (1-2) als eine Funktion des beobachteten Lichtes (7), wobei die Auswahl basierend auf einem gewissen Intensitätswert des emittierten Lichtes (7) vorgenommen wird; und

automatisches Trennen der Produkte (1-2) von dem oben erwähnten Produktstrom (4) als eine Funktion der Auswahl.

2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass Verwendung der Fluoreszenzqualitäten für die Emission gemacht wird, insbesondere der Tatsache, dass die abgetasteten Produkte (1-2) entweder fluoreszieren oder nicht.

3. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass es zum Sortieren von Chlorophyll enthaltenden Nahrungsmitteln verwendet wird, insbesondere zur Auswahl von nichtessbaren Produkten (2) aus den Nahrungsmitteln.

4. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass, wenn emittiertes Licht (7) beobachtet wird, dies in einem Bereich getan wird, in dem es einen Wert in der Größenordnung von etwa 715 Nanometern hat.

5. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass für den emittierenden Hintergrund Verwendung von einer Oberfläche (21) gemacht wird, welche sich in der Breite des Produktstroms (4) erstreckt, die auf der Seite, auf die das Licht (6) geworfen wird, sphärisch ist.

6. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Hintergrund aus einem Element (20) in Form einer zylindrischen Walze besteht.

7. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Abtastung mittels eines Lasers stattfindet.

8. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Abtastung ausgeführt wird, in dem man einen Laserstrahl (10) diagonal über dem Produktstrom (4) in systematischer Weise bewegt.

9. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass Verwendung von einem Scan- bzw. Abtastsystem mit einem sich bewegenden Spiegel (35) gemacht wird, vorzugsweise mit einem sich drehenden Polygon-Spiegel und dadurch, dass das emittierte Licht (7) über den gleichen Spiegel (35) zurückgeleitet wird.

10. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Abtastung mittels eines festen Lichtbandes oder einer Reihe von Lichtpunkten stattfindet, die auf die Produkte (1-2) gerichtet sind, welche über die Breite des Produktstroms (4) vorbeilaufen, wobei zumindest das emittierte Licht (7) mittels einer Kamera beobachtet wird.

11. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Produkte (1-2) in einer einzigen Ebene an den Platz gebracht werden, wo sie abgetastet werden, und zwar über einen Tisch, insbesondere einen vibrierenden Tisch (29), ein Band oder ähnliches, welche mit in Längsrichtung verlaufenden Leitungen oder Nuten versehen sind oder nicht.

12. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Produkte (1-2) frei herunterfallen, und dadurch, dass die zu trennenden Produkte (1-2) mittels Düsen (15) auseinander bewegt werden, die über die Breite (B) des Produktstroms angeordnet sind, und die einzeln oder in Gruppen als eine Funktion der gemachten Beobachtungen aktiviert werden.

13. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die zu sortierenden Produkte (1-2) von zwei Seiten abgetastet werden, die gegenüberliegend zum Produktstrom (4) gelegen sind.

14. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass es mit einer Farbsortierung kombiniert ist, wobei die Sortierung auf der Grundlage einer Lichtreflektion ausgeführt werden.

15. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass unterschiedliche Laserstrahlen verwendet werden, und dadurch, dass die unterschiedlichen Laserstrahlen simultan entlang des gleichen Lichtpfades geführt werden, wobei sie möglicherweise geringfügig bezüglich einander verschoben werden.

16. Vorrichtung zum Sortieren von Produkten gemäß dem Verfahren nach einem der vorhergehenden Ansprüche, wobei Abfall von Produkten getrennt wird, die Chlorophyll enthalten, dadurch gekennzeichnet, dass sie zumindest aus der folgenden Kombination besteht:

Mittel (28) zum Fördern der zu sortierenden Produkte (1-2) in Form eines Produktstroms (4), der sich über die Breite (B) eines bestimmten Pfades (3) erstreckt;

Mittel zum Abtasten der zu sortierenden Produkte (1-2) über die Breite des Produktstroms (4), welche aus Mitteln (5) zum Werfen bzw. Strahlen von Licht mit einer Wellenlänge von 640 bis 680 Nanometern auf die Produkte (1-2) und auf einen Hintergrund (20) bestehen, der fluoresziert, wenn er mit dem darauf gestrahlten Licht beleuchtet wird, so dass Produkte (1), die Chlorophyll enthalten, und der Hintergrund (20) Licht (7) emittieren werden, welches praktisch die gleiche Wellenlänge hat und weiter Mittel (8) um dieses emittierte Licht in einem Bereich von 690 bis 740 Nanometer zu beobachten;

einen optischen Bandpassfilter zum Beobachten des Lichtes (7), welches von den betreffenden Produkten (1) emittiert wird;

Mittel (13) zum Vornehmen einer Auswahl zwischen den abgetasteten Produkten (1-2) als eine Funktion eines gewissen Intensitätswertes des emittierten Lichtes (7); und

Mittel (14) zum automatischen Trennen der Produkte (1-2) von dem oben erwähnten Produktstrom (4) als eine Funktion der Auswahl.

17. Vorrichtung nach Anspruch 16, dadurch gekennzeichnet, dass die Mittel (5) zum Werfen von Licht (6) auf die Produkte (1-2) aus einem Laser bestehen, der einen Laserstrahl (10) erzeugt, genauso wie aus optischen Mitteln die diesen Laserstrahl (10) in Breitenrichtung über den Produktstrom (4) bewegbar machen.

18. Vorrichtung nach Anspruch 16 oder 17, dadurch gekennzeichnet, dass die Mittel (8) zum Beobachten von Licht (7) in dem Spektrum, in dem das emittierte Licht (7) ausgestrahlt wird, aus optischen Mitteln bestehen, die das emittierte Licht (7) sammeln und es zu den Mitteln (13) zum Ausführen der Auswahl leiten, wobei diese optischen Mittel zumindest einen optisch eingestellten Filter (11) aufweisen.

19. Vorrichtung nach einem der Ansprüche 16 bis 18, dadurch gekennzeichnet, dass die Mittel (28) zum Fördern der zu sortierenden Produkte (1-2) in Form eines Produktstroms (4), der sich über die Breite (B) eines bestimmten Pfades (3) erstreckt, hauptsächlich aus einem vibrierenden Tisch (29) bestehen, auf dem die Produkte (1-2) angeordnet sind, und aufeinander folgend weg über dessen Kante (30) vibriert werden.

20. Vorrichtung nach einem der Ansprüche 16 bis 19, dadurch gekennzeichnet, dass die Mittel (14) zum automatischen Trennen der Produkte (1-2) von dem oben erwähnten Produktstrom (4) als eine Funktion der Auswahl aus einer Reihe von Düsen (15) bestehen, die als eine Funktion der vorgenommenen Auswahl und der zu realisierenden Trennung aktiviert werden.

21. Vorrichtung nach einem der Ansprüche 16 bis 20, dadurch gekennzeichnet, dass die Mittel (28) zum Fördern der zu sortierenden Produkte (1-2) in Form eines Produktstroms (4), der sich über die Breite (B) eines gewissen Pfades (3) erstreckt, hauptsächlich aus einer Walze (36) bestehen, die mit Einlässen (37) an ihrer Oberfläche versehen ist, an welche die Produkte (1-2) gesaugt werden, und dadurch, dass die Mittel zum automatischen Vornehmen einer Trennung als einer Funktion der Auswahl aus Mitteln bestehen, die es möglich machen, die betreffenden Einlässe (37) selektiv zu steuern.

22. Vorrichtung nach einem der Ansprüche 16 bis 21, dadurch gekennzeichnet, dass die Mittel zum Abtasten der zu sortierenden Produkte (1-2) über die Breite (B) des Produktstroms (4) ein oder mehrere Elemente (20) aufweisen, die einen Licht emittierenden Hintergrund bilden.

23. Vorrichtung nach Anspruch 22, dadurch gekennzeichnet, dass die oben erwähnten Elemente (20) aus einer zylindrischen Walze mit einer fluoreszierenden Oberfläche (21) bestehen.

Revendications

1. Procédé pour trier des produits, par lequel des déchets sont séparés de produits contenant de la chlorophylle, caractérisé en ce qu'il comprend au moins :

convoyer les produits (1-2) à trier sous la forme d'un flux de produits (4) s'étendant sur la largeur (B) d'un chemin spécifique (3) ;

analyser les produits (1-2) à trier sur la largeur (B) du flux de produits (4) en projetant sur les produits (1-2) de la lumière (6) ayant une longueur d'onde comprise entre 640 et 680 nanomètres, de sorte que des produits (1) contenant de la chlorophylle vont émettre de la lumière (7), et observer la lumière émise (7) dans une plage de longueurs d'onde de 690 à 740 nanomètres ;

utiliser un passe-bande optique afin d'observer la lumière (7) qui est émise par les produits (1) concernés ;

utiliser un arrière-plan qui va émettre de la lumière lorsqu'il est éclairé et qui va devenir fluorescent, de sorte que la lumière projetée (6) va aussi produire un effet d'émission dans les endroits où elle n'est pas projetée sur un produit (1-2), la lumière émise par l'arrière-plan ayant pratiquement la même longueur d'onde que la lumière qui est émise par les produits (1) contenant de la chlorophylle ;

faire une sélection entre les produits analysés (1-2) en fonction de la lumière observée (7), la sélection étant faite sur une certaine valeur d'intensité de la lumière émise (7) ; et

séparer automatiquement les produits (1-2) à partir du flux de produits (4) susmentionné en fonction de la sélection.

2. Procédé selon la revendication 1, caractérisé en ce qu'on utilise les qualités de fluorescence pour l'émission, en particulier le fait que les produits analysés (1-2) sont ou pas fluorescents.

3. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il est utilisé pour trier les des produits alimentaires contenant de la chlorophylle, en particulier pour la sélection de produits non alimentaires (2) parmi des produits alimentaires.

4. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que lorsque la lumière émise (7) est observée, cela est fait dans une plage qui a une valeur de l'ordre de 715 nanomètres.

5. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que, pour l'arrière-plan émetteur, on utilise une surface (21) s'étendant sur la largeur du flux de produits (4) qui est sphérique sur le côté ou la lumière (6) est projetée.

6. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que l'arrière-plan est constitué d'un élément (20) ayant la forme d'un rouleau cylindrique.

7. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que l'analyse se fait au moyen d'un laser.

8. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que l'analyse est réalisée en faisant en sorte qu'un faisceau laser (10) se déplace en diagonale sur le flux de produits (4) de manière systématique.

9. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce qu'on utilise un système d'analyse muni d'un miroir mobile (35), de préférence un miroir polygonal rotatif, et en ce que la lumière émise (7) est renvoyée par l'intermédiaire du même miroir (35).

10. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que l'analyse se fait au moyen d'une bande de lumière fixe ou d'une série de points lumineux dirigés sur les produits (1-2) qui passent sur la largeur du flux de produits (4), dans lequel au moins la lumière émise (7) est observée au moyen d'une caméra.

11. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que les produits (1-2) sont amenés dans un même plan à l'endroit où ils doivent être analysés, par l'intermédiaire d'une table, en particulier une table vibrante (29), un tapis roulant ou similaire, muni ou pas de conduits ou de sillons longitudinaux.

12. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que les produits (1-2) tombent librement et en ce que les produits (1-2) à séparer sont écartés aux moyens de buses (15) qui sont dressées sur la largeur (B) du flux de produits et qui sont activées individuellement ou en groupes en fonction des observations réalisées.

13. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que les produits (1-2) à trier sont analysés à partir de deux côtés, situés opposés au flux de produits (4).

14. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il est combiné avec un tri par couleur dans lequel le tri est réalisé sur la base de réflexion lumineuse.

15. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce qu'on utilise des faisceaux laser différents et en ce que les faisceaux laser différents sont guidés simultanément suivant le même chemin de de lumière, éventuellement légèrement décalés l'un par rapport à l'autre.

16. Dispositif pour trier des produits selon le procédé de l'une quelconque des revendications précédentes, par lequel des déchets sont séparés de produits contenant de la chlorophylle, caractérisé en ce qu'il comprend au moins en combinaison :

des moyens (28) pour convoyer les produits (1-2) à trier sous la forme d'un flux de produits (4) s'étendant sur la largeur (B) d'un certain chemin (3) ;

des moyens pour analyser les produits (1-2) à trier sur la largeur (B) du flux de produits (4), constitués de moyens (5) pour projeter de la lumière (6), ayant une longueur d'onde comprise entre 640 et 680 nanomètres, sur les produits (1-2) et sur un arrière-plan (20) qui devient fluorescent lorsqu'il est éclairé par la lumière projetée (6), de sorte que les produits (1) contenant de la chlorophylle et l'arrière-plan (20) vont émettre de la lumière (7) ayant pratiquement la même longueur d'onde, et de moyens (8) pour observer cette lumière émise dans une plage de longueurs d'onde de 690 à 740 nanomètres ;

un passe-bande optique afin d'observer la lumière (7) qui est émise par les produits (1) concernés ;

des moyens (13) pour faire une sélection entre les produits analysés (1-2) en fonction d'une certaine valeur d'intensité de la lumière émise (7) ; et

des moyens (14 pour séparer automatiquement les produits (1-2) à partir du flux de produits (4) susmentionné en fonction de la sélection.

17. Dispositif selon la revendication 16, caractérisé en ce que les moyens (5) pour projeter de la lumière (6) sur les produits (1-2) sont constitués d'un laser produisant un faisceau laser (10), ainsi que de moyens optiques qui font en sorte de que ce faisceau laser (10) se déplace dans la largeur sur le flux de produits (4).

18. Dispositif selon la revendication 16 ou 17, caractérisé en ce que les moyens (8) pour observer la lumière (7) dans le spectre dans lequel la lumière émise (7) est projetée, sont constitués de moyens optiques qui recueillent la lumière émise (7) et la guident vers les moyens (13) pour réaliser la sélection, d'où il résulte que ces moyens optiques comprennent au moins un filtre optiquement ajusté (11).

19. Dispositif selon l'une quelconque des revendications 16 à 18, caractérisé en ce que les moyens (28) pour convoyer les produits (1-2) à trier sous la forme d'un flux de produits (4) s'étendant sur la largeur (B) d'un certain trajet (3) sont constitués principalement d'une table vibrante (29) sur laquelle les produits (1-2) sont placés et sont ensuite écartés par vibrations sur le bord (30).

20. Dispositif selon l'une quelconque des revendications 16 à 19, caractérisé en ce que les moyens (14) pour séparer automatiquement les produits (1-2) à partir du flux de produits (4) susmentionné en fonction de la sélection sont constitués d'une série de buses (15) qui sont activées en fonction de la sélection faite et de la séparation à réaliser.

21. Dispositif selon l'une quelconque des revendications 16 à 20, caractérisé en ce que les moyens (28) pour convoyer les produits (1-2) à trier sous la forme d'un flux de produits (4) s'étendant sur de la largeur (B) d'un certain trajet (3) sont principalement constitués d'un tambour (36) qui est muni d'entrées (37) sur sa surface contre laquelle les produits (1-2) sont aspirés, et en ce que les moyens pour réaliser automatiquement une séparation en fonction de la sélection sont constitués de moyens qui permettent de contrôler sélectivement les entrées (37) concernées.

22. Dispositif selon l'une quelconque des revendications 16 à 21, caractérisé en ce que les moyens pour analyser les produits (1-2) à trier sur la largeur (B) du flux de produits (4) contiennent un ou plusieurs éléments (20) formant un arrière-plan émetteur de lumière.

23. Dispositif selon la revendication 22, caractérisé en ce que les éléments susmentionnés (20) sont constitués d'un rouleau cylindrique ayant une surface fluorescente (21).

Drawing